Insert core for slide shut-off device



May 21, 963 J. WOODBURN, .1R

INSERT CORE FOR sLDE SHUT-OFF DEVICE 2 Sheets-Sheet l Filed Aug. 24,1960 May 21, 963 1. wooDBURN, JR 3,090,090

INSERT CORE FOR SLIDE SHUT-OFF DEVICE 2 Sheets-Sheet 2 Filed Aug. 24,1960 i2 .sa 52 5J"150 35 OO 0 o 100 -Jao 118 i/zg INVENTOR.

128 Q22/ 13%/ 32 Jannes gorffzmyn. BY

United States Patent O 3,090,096 ENSERT CURE FR SLIDE SHU'BFF DEVCE.lames Woodburn, Sir., Wheaton, lll., assignor to Arnsted IndustriesIncorporated, Chicago, Ill., a corporation of New Jersey Filed Aug. 24,196i), Ser. No. 51,657 4 Claims. (Ci. 2.2-84) This invention relates tothe art of bottom casting in which molten metal or other fluid materialis Iforced into a bottom gate o-f a mold, and the invention relates moreparticularly to novel means for cutting off flow of such material and toa method of producing such means.

According to prior art pnactices, the fluid material enters the gatethrough -an aperture of a cut-off slide which is actuated to `close thegate when the mold has been filled. According to such practices, theaperture has been bushed to accommodate reuse of the slide.

However, such practices have been limited to low melting point alloyssuch as white metal and other low melting point nonferrous metals whichdo not cause excessive erosion `of the bushings during the pouring.

According to .the invention, it has been discovered that conventionalcore sand bushings, although eiective in such prior art practices, arenot suitable for the casting of iron, steel, and similar high meltingpoint ferrous and nonferrous metals which must be poured at temperaturesin excess of 1500 F. and at velocities which cause excessive erosion ofsuch prior ant bushings.

Early efforts to solve this problem involved the substitution of a firedrefractory material `for prior art sand core bushings; however, suchmaterial proved to be costly and to require expensive molding ormachining to suitable form.

According to the invention it has been discovered that a satisfactorycomposite bushing can be produced by forming a conventional core sandmix sleeve around the perimeter of a tired refractory liner in suchmanner that the sleeve and liner are bonded to each other to form acomposite bushing which can be quickly and economically assembled bymanual insertion intothe top of an aperture in a cut-off slide.

The foregoing and other objects of this invention will become apparent:from a consideration of the ifollowing specification and theaccompanying drawings, wherein:

FIGURE 1 is a perspective View of casting appanatus embodying apreferred form of the novel composite bushma;

FIGURE 2 is atop plan View ofthe cut-off slide assembly shown in yFIGUREl;

FIGURE 3 is a fragmentary sectional view on line 3 3 of FIGURE 2;

FIGURE 4 is a Ifragmentary side elevational view of the structure shownin FIGURE 2;

FIGURE 5 is a sectional view on Iline 5 5 of FIG- URE 4;

FIGURE 6 is a central vertical sectional View through a core box andcomposite bushing `formed therein according to one manner of practicingthe novel process; and

FIGURE 7 is a view corresponding -to FIGURE 6 but show-ing anothermanner of practicing the novel process.

Describing the invention in detail, a mold .assembly generallydesignated 2 (FIGURE 1) comprises a mold 4 which may be of a chillmaterial, such as graphite or of any other desired ceramic material wellknown in the art, such as sand or shell. The assembly 2 also cornprisesa car 6 to which the mold 4 may be clamped by conventional clamps 7 orby force of gravity. The mold 4 and car 6, during a pouring oper-ation,as hereinafter described, move together as a unit or assembly 2 and maybe interconnected in any desired manner.

3,690,096 Patented May 21, 196s ICC The car 6 comprises wheels 8 whichroll on tracks 10 and 'also comprises a cut-off or gate closing devicegenerally `designated 12. The cut-off 12 is best seen in FIG- URES 2 4and includes a slide support 14 having an opening or hole 15 with abushing 16 (FIGURE 3) formed .as hereinafter described. The slidesupport 14 has a cut-out or slot 18 (FIGURE 2) pantly defined by aninner edge 20 for a purpose hereinafter described.

A slide or plate 22 preferably of cast iron, copper or -any otherdesired chill material is slidably mounted on the support 14 andcomprises an opening or aperture 24 having la bushing 26 similar in formand composition to bushing 16, as hereinafter described. The slide 22 issupported within a channel 28 (FIGURE 4) of the support 14 and is seated-along a surface thereof immediately below another channel '34 withinwhich is positioned a loose insert 36 (FIGURES 2 and 3) which iscomplementary -to and removably mounted in an opening 3S of a top plateor panel 4t) of the car 6.

The support 14 is releasably interlocked with the panel dit by means ofears 42 on the support having apertures within which are received lugs46 on the underside of panel 40. The lugs 46 are slotted to receivewedge keys 48 which are driven to locking position shown in FIGURE 4 andwhich may be quickly removed by an impact against the small ends of thekeys 48.

The insert 36 is provided with an opening or aperture 50 having abushing 52 (FIGURE 3) similar in form and material to bushings 16 and'26, whereby when apertures li5, 24 and 5d are aligned, they define acontinuous passage for the ow ofv molten metal into a gate 54 (FIG- URE3) of the mold 4.

The `assembly Z rolls along rails 10= (FIGURE 1) until the apertures 15,24 and Sti are located in vertical alignment with the top of a pouringtube 58 (FIGURE 4), the lower end of which communicates with a source offluid material (not shown) lto be cast, such Ias a ladle of moltensteel. Under these conditions, the wheels 8 are supported by railsegments 10a which are separable from rails 1d and are verticallymovable.

The segments 10a are supported by a frame 60 which is in turn supportedat its corner-s, as by conventional wormgear screw jacks 62. The jacksare mounted on founda-` tion-supported beams 66 and raise or lower theframe 60 as desired. The car 6 is guided at each side thereof in alignedrelationship with the top of tube 58 by foundationmounted guide rails 71(FIGURE l) which snugly confine therebetween a pin 73 on panel 4i) ofcar 6.

When the assembly .2 is aligned with the top of tube 58, the jacks 62are actuated to lower the frame 60 until a tapered recess 74 in thebottom of the support 14 engages a complementary tapered portion 76(FIGURE 4) of the upper end of tube 58. The frame continues to loweruntil the support `i4- is clamped by force of gravity or Iby other means(not shown) against the tapered portion of tube 58 to afford a sealtight to liquid metal between the tube and the support 14, whereupon themolten steel in which the tube 14 is immersed is pressurized (as forexample in the manner disclosed by U.S. Letters Patent No. 2,847,739is-sued August 19, 1958 to E. Q. Sylvester) to flow the metal upwardlythrough apertures 15, 24 and Sii and gate 54 until the mold has beenfilled. Tilting of the car 6 during pouring is limited by lugs 75 (FIG-URE 1) mounted on the top of brackets 114, hereinafter described.

After the mold has been filled the slide 22 is actuated, as hereinafterdescribed, to cut-olf flow of molten metal through the gate, whereuponpressure on the molten metal is released, the rail `segments lita areelevated to mating relationship with rails 10, andl the assembly 2 isrolled along the rails away from tube 58, andv another assembly 2 isrolled into position and poured as heretofore described.`

The manner in which the cut-off 12 is actuated can best be seen inFIGURE 4, wherein it will be seen that when the assembly 2 is supportedon top of the tube S8, a power device 78 mounted on a cover 80 of achamber or tank 81 containing the molten steel is disposed between theslide 22 and an abutment 82 depending from the underside of car panel 40so that actuation of the device 78, as by hydraulic or pneumaticpressure, to expand the device 78 axially thereof causes a cylindermember 84 of the device 78 to engage the abutment 82 and a ram 0r pistonmember 86 of the device 78 to engage the cut-off slide 22.

The device 78 has a limited stroke and at the endY of said stroke, theslide 22 is at a position whereat its aperture 24 is beyond edge 20 ofthe support 14, whereupon molten metal in aperture 24 is dumped throughslot 18 so that the lbushing 26 need not be replaced for each pouringoperation. Also release of pressure on the molten metal in the tank 81dumps the metal in bushing 16 so that it need not lbe replaced for eachpouring operation.

The device 78 is afforded a oating support so that, upon actuationthereof, the forces developed by the device 78 to actuate the cut-oi 12to closed position are self-contained within the assembly 2. Thissupport comprises a bracket 88 mounted on top of the cover 80 as bywelding at 90. The bracket comprises a V-shaped channel 92 (FIGURE 5)-within which a complementary slide 94 is positioned. The cylindermember 84 is clamped into the slide 94 by clamp rollers 98 on levers 100pivotally fulcrumed -at 102 (FIGURE 5) to the slide 94 and actuated by acompression clamping spring 104.

Upon energization of device 78, as heretofore described, the slide 94permits enough axial movement of the device 78 so that the forcesdeveloped thereby are self-contained within assembly 2 and substantiallyno reactive forces are transmitted to bracket 88 or cover 80.

Upon removal of cylinder 84 from the clamps 98, which can beaccomplished by manually lifting the cylinder to compress spring 104,the spring 104 is held in position upon bosses -112 of levers 100 by aslight force provided by a tension spring 113 connected to the lowerends of lever 100. Y Y

' It may be noted that the cover 80l may be clamped to the top of itscontainer 81 by clamp means (not shown) mounted on foundation-supportedbrackets 114, and the rail segments a may be manually removed from andreplaced upon the frame 60 to accommodate insertion and removal of thecover 80 and a ladle (not shown) of molten steel into which the tube 58extends. The construction of the container 81, the ladleV (not shown),the cover 80 and tube 58 is per se no part of the present invention andmay be of the type disclosed in said U.S. Letters Patent, or if desired,may be of any other desired construction and arrangement, with the tubemounted on the cover or elsewhere in communication with the molten steelin the container 81.

It should 'be noted that bushings 16, 26 and 52 are ilanged at theirupper ends so that in their aligned position shown in FIGURE 7, theflange of bushing 16 engages slide 22, the liange of `bushing 26 engagesinsert 36 and the flange of bushing 52 engages the mold 4 around itsgate 54.

According to the inventiomeach bushing 16, 26, and 52 is of novel formand comprises a prered refractory -liner 118 bonded to a flanged sleeve120, as shown for example in FIGURE 6, wherein a novel method of makingsuch a bushing is disclosed. The liner 118 is formed of `a hard tiredmaterial such as graphite containing clayrefractories so that the liner1-18 does not erode substantially during the pouring and shut-oft stepsof a cycle as heretofore described. Such material cannot beVeconomically molded to the desired bushing form and, according to prior`art practices, must be machined to that shape from a segment of arefractory tube, which is also an expensive procedure.

According to the invention, the liner 118 is cut to desired length froma standard tube and is sleeved over a complementary boss or center arbor119 of an annular member 122 having -a metal ring 124 sleeved thereon toform a metal core box which can be preheated to a desired temperature.The ring 124- is recessed as at 126 to define a larger diameter portionof the opening in ring 1.24, within which opening the liner 118 ispositioned.

A mixture of conventional shell mold Zircon sand and 2% (by volume)phenolic liquid thermosetting resinis poured around the liner I118 andis struck olf ush with the top of the ring 124. rIhis mixture bonds withthe liner 118, the contacting surface of which is of sufficientlyirregular contour to aiord a good bond. After the resin has set, thenovel composite bushing 118120 is removed from the core box 122, `124 byejecter pins 128 having release springs 129.

FIGURE 7 shows a modification of the novel process wherein the shellmold sand mixture heretofore described is blown into core box 122, 124by a conventional blow head 138, the member 122 being provided withsuitable vents 132 screened as at 134.

It will be understood that, if desired, the apparatus of FIGURE 7 can beutilized to form a sleeve 120 from a sodium silicate-CO2 bonded sand byblowing into core box 122, 124 a mixture of silica sand and 5% (byvolume) sodium silicate. In this practice, the core box 122, 124 is notheated and after the blow head 130 has been removed, a similar blow headis positioned on core box 122, 124 to -blow CO2 gas through the core boxuntil the sleeve has hardened.

Also, if desired, the sleeve 120 may be formed in the core box 122, 1-24of 4FIGURE 7 by charging blow head with a conventional mixture of, forexample, l1/% (by volume) corn cereal, 2% (by volume) linseed oil, 3%(by volume) water, and the remainder conventional silica core sand.After the core box 122, 124 has been filled with this mixture by blowhead 130, the latter is removed, and the core is ejected and baked in aconventional core oven until hard, as for example, at about 425 F. forabout two hours.

After the composite bushing L18-4120 has been formed as heretoforedescribed, it is hand tted into an assembly such as heretobeforedescribed in connection with FIG- URES 2 and 3, and it will beunderstood that all bushings 16, 26 and 52 may be formed as compositebushings 118-120 and may be assembled in the foregoing manner.

Moreover, if desired, the composite bushing 118-120 may be formed insitu within its opening 15, 24, or 50 by eliminating member 124 andinserting member 122 in such opening and thereafter forming the bushing118- 120 by any of the foregoing methods.

I claim:

l, In a device for pouring molten high melting point metal into a moldthrough a bottom gate, the combination of a cut-ohc slide having anaperture registered with -the gate, a bushing in said aperturecomprising a sleeve with a flange recessed in the slide, a hollowcylindrical refractory liner in the sleeve, said sleeve being snuglytted in the aperture and being formed of sand particles bonded to eachother and to said liner by a binder said liner being formed of arefractory material more resistant to erosion by said molten metal thansaid sleeve, and means for actuating the slide to a position where itcuts olf fiow of said molten metal from said bottom gate when the moldhas been tllled therewith.

2. In a method of forming a bushing for a cut-off slide having anaperture through which molten high melting point metal flows into a moldgate, the steps of inserting a refractory liner into said aperture, andthen filling the aperture around said liner with a mixture of sandparticles and fluid bonding material which, when set, bonds theparticles to each other and to the liner and slide, to form a sleevearound the liner.

3. In a device for pouring molten high melting point metal into a moldthrough a bottom gate, the combination of a cut-off slide having anaperture registrable with the gate, a bushing in said aperturecomprising a sleeve with a ilange recessed in the slide, a cylindricallyshaped refractory liner in the sleeve, said sleeve being snugly tted inthe aperture and being formed of sand particles bonded to each other andto said liner by a binder.

4. In a cut-off device for molds for high melting point metals, thecombination of: a cut-off slide having an aperture therethrough; abushing in said aperture com- 15 prising a sleeve with a ange recessedin said slide; a refractory liner in said sleeve; said sleeve beingsnugly tted in the aperture and being formed of sand particles bonded toeach other and to said liner by a binder; said liner being formed of arefractory material more resistant to erosion by said molten metal thansaid sleeve.

References Cited in the file of this patent UNITED STATES PATENTSPhillips Aug. 16, 1938 2,309,608 Wessel Jan. 26, 1943 2,495,064 HorvathI an. 17, 1950 2,757,219 Clough et al July 31, 1956 2,836,865 Bravard etal. June 3, 1958

1. IN A DEVICE FOR POURING MOLTEN HIGH MELTING POINT METAL INTO A MOLDTHROUGH A BOTTOM GATE, THE COMBINATION OF A CUT-OFF SLIDE HAVING ANAPERTURE REGISTERED WITH THE GATE, A BUSHING IN SAID APERTURE COMPRISINGA SLEEVE WITH A FLANGE RECESSED IN THE SLIDE, A HOLLOW CYLINDRICALREFRACTORY LINER IN THE SLEEVE, SAID SLEEVE BEING SNUGLY FITTED IN THEAPERTURE AND BEING FORMED OF SAND PARTICLES BONDED TO EACH OTHER AND TOSAID LINER BY A BINDER SAID LINER BEING FORMED OF A REFRACTORY MATERIALMORE RESISTANT TO EROSION BY SAID MOLTEN METAL THAN SAID SLEEVE, ANDMEANS FOR ACTUATING THE SLIDE TO A POSITION WHERE IT CUTS OFF FLOW OFSAID MOLTEN METAL FROM SAID BOTTOM GATE WHEN THE MOLD HAS BEEN FILLEDTHEREWITH.